11-6
Cisco Catalyst Blade Switch 3130 and 3032 for Dell Software Configuration Guide
OL-12247-04
Chapter 11 Configuring Interface Characteristics
Understanding Interface Types
The default action, when a VLAN has multiple ports, is that the SVI goes down when all ports in the
VLAN go down. You can use the SVI autostate exclude feature to configure a port so that it is not
included in the SVI line-state up-an- down calculation. For example, if the only active port on the VLAN
is a monitoring port, you might configure autostate exclude on that port so that the VLAN goes down
when all other ports go down. When enabled on a port,
autostate exclude
applies to all VLANs that are
enabled on that port.
The VLAN interface is brought up when one Layer 2 port in the VLAN has had time to converge
(transition from STP listening-learning state to forwarding state). This prevents features such as routing
protocols from using the VLAN interface as if it were fully operational and minimizes other problems,
such as routing black holes. For information about configuring autostate exclude, see the
SVI Autostate Exclude” section on page 11-25
.
EtherChannel Port Groups
EtherChannel port groups treat multiple switch ports as one switch port. These port groups act as a single
logical port for high-bandwidth connections between switches or between switches and servers. An
EtherChannel balances the traffic load across the links in the channel. If a link within the EtherChannel
fails, traffic previously carried over the failed link changes to the remaining links. You can group
multiple trunk ports into one logical trunk port, group multiple access ports into one logical access port,
group multiple tunnel ports into one logical tunnel port, or group multiple routed ports into one logical
routed port. Most protocols operate over either single ports or aggregated switch ports and do not
recognize the physical ports within the port group. Exceptions are the DTP, the Cisco Discovery
Protocol (CDP), and the Port Aggregation Protocol (PAgP), which operate only on physical ports.
When you configure an EtherChannel, you create a port-channel logical interface and assign an interface
to the EtherChannel. For Layer 3 interfaces, you manually create the logical interface by using the
interface port-channel
global configuration command. Then you manually assign an interface to the
EtherChannel by using the
channel-group
interface configuration command. For Layer 2 interfaces, use
the
channel-group
interface configuration command to dynamically create the port-channel logical
interface. This command binds the physical and logical ports together. For more information, see
Chapter 37, “Configuring EtherChannels and Link-State Tracking.”
10-Gigabit Ethernet Interfaces
The switch has two 10-Gigabit Ethernet module slots. For uplink connections to other switches and
routers, use the Cisco TwinGig Converter Modules.
A 10-Gigabit Ethernet interface operates only in full-duplex mode. The interface can be configured as a
switched or routed port.
For more information about the Cisco TwinGig Converter Module, see the switch hardware installation
guide and your transceiver module documentation.
